Carcinoma of the parathyroid.

: The histologic diagnosis of carcinoma of the parathyroid is difficult to make, and invasion of contiguous structures or metastasis must be present before the diagnosis can be established. The serum calcium level is usually high, and the tumor is palpable in approximately one half of the patients. A case of parathyroid carcinoma is presented in which the patient had a high serum calcium level, a palpable tumor with invasion of the thyroid gland and metastasis to a local lymph node. Treatment consists of en bloc resection of the tumor and, if possiblethe metastasis. Usually an ipsilateral neck dissection is indicated.